#theodolite — Public Fediverse posts

Atmospheric refraction, due to the different temperature/altitude profile in the atmosphere at different times of day...makes distant mountains appear taller or shorter.

The attached photo is a comparison of what I shot yesterday afternoon and this morning. The camera was set up within inches of the same location for both shots, and those mountains are between 50 and 120 miles away...so I'm saying that any parallax effect from camera location is essentially zero.

I have annotated with arrows where it's easy to make a comparison of how the near and far ridge lines overlap differently in the two photos.

This is a follow up to:
https://universeodon.com/@KrajciTom/115673789231444526

Imagine the care that was needed to conduct surveys before the GPS/GNSS era:
https://explorersweb.com/the-five-men-who-measured-mount-everest/

"The Great Theodolite built by Troughton & Simms in London stood nearly 1.5m high, had a horizontal circle one meter in diameter, and could read angles to a single second of arc. Moving it required 30 porters and sometimes elephants."

"The reduction of Nicolson’s observations was a colossal task. Each ray from each station had to be corrected for instrumental error, for temperature and pressure, and for the curvature of the Earth. Above all, they needed to correct for atmospheric refraction, which at those distances could amount to six or seven minutes of arc and change from hour to hour."

#Atmosphere #Refraction #Physics #Math #GIS #Datum #Survey #Geodetic #Map #Optics #Science #Parallax #Cool #NewMexico #Theodolite

#astronomy #astrophotography #theodolite app

Tips use Theodolite app on my phone to determine degrees above the horizon my local view of the sky might be blocked. Or not so local views

Nearby trees are blocking the closest most likely view of the comet visiting now- I was only able to view the last one via my iPhones (14 pro) night mode photography.

Want to increase my chances, scout nearby low horizon clearance. Usually on road or pajamas under best conditions
https://reentry.codl.fr/@apod/statuses/01K7DW97M697P5EVEBNJMGKK13

Tech in Plain Sight: Theodolites https://hackaday.com/2024/06/03/tech-in-plain-sight-theodolites/ #HackadayColumns #Engineering #theodolite

Tech in Plain Sight: Theodolites - We take it for granted that you can look at your phone and tell exactly where you ... - https://hackaday.com/2024/06/03/tech-in-plain-sight-theodolites/ #hackadaycolumns #engineering #theodolite

The evolution of modern surveying instruments experienced an inflection point in the early 20th Century when multiple sciences converged. A visit to an optics museum spurred a deeper look into one such backstory. https://bt.e-ditionsbyfry.com/publication/?m=36207&i=786435&p=22&ver=html5
#surveying #geomatics #theodolite #zeiss #jena